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Introducing light energy into the charging/discharging process is an effective strategy to reduce the overpotential of Li−O 2 battery, which leads that the battery has higher energy conversion efficiency and better battery performance. However, the development has been hampered by the lack of suitable photocatalysts and cathode structure to accommodate the insoluble Li 2 O 2. In order to overcome the aforementioned difficulties, a bifunctional photocatalyst α-Fe 2 O 3 /SnO 2 (FS) heterojunction was designed as the cathode to improve the charging/discharging overpotentials simultaneously. The photogenerated electrons and holes from FS participated in the oxygen reduction reaction (ORR) and oxygen revolution reaction (OER) under illumination, giving rise to an ultra-low charging/discharging overpotential of 0.01 V (energy efficiency up to 99.7%), which improved the electrochemical reaction kinetics of the Li−O 2 battery strikingly. In addition, the FS cathode exhibited excellent cycle stability under light (the battery energy efficiency can still maintain 80% after 252 cycles). The bifunctional catalyst designed in this paper has profoundly proved that the band engineering strategy can effectively utilize solar energy and provide important insights for understanding the mechanism of photo-assisted Li−O 2 battery. [Display omitted] • Light energy into the charging/discharging process is an effective strategy to reduce the overpotential of Li−O 2 battery. • A bifunctional photocatalyst α-Fe 2 O 3 /SnO 2 (FS) heterojunction was designed as the cathode. • Band engineering strategy effectively utilize solar energy • Band engineering strategy provide important insights for understanding the mechanism of photo-assisted Li−O 2 battery [ABSTRACT FROM AUTHOR]

Photocatalytic advanced oxidation has been widely studied for purifying organic polluted water bodies. The molding of powder catalyst is able to solve the problems of difficult recycling and secondary pollution, and it further promotes the practical application of photocatalytic materials. In this work, PAN and PVDF are used as precursors to prepare polymer blended fiber membranes using electrostatic spinning technique. In order to achieving the degradation of Rh-B via photocatalysis, PAPV@MT photocatalytic membrane is prepared in company with acrylic acid modification and in-situ growth of MoS 2 /TiO 2 via hydrothermal method. As a result, the photocatalytic film exhibits good stretchability, flexibility, and high catalytic degradation capacity. At the same time, the special structure of the hydrophobic surface on the membrane layer enables the photocatalytic membrane to hold a three-phase, i.e., solid-liquid-gas. Considering Rh-B as target contaminant, waste water can be decolorized within 150 min with a removal rate of 80%, benefiting from the introduction of MoS 2. It promotes the separation of electron-hole pairs, so that its catalytic capacity is significantly enhanced. Therefore, the membranes reported here provide ideas for practical applications, with properties of stable, highly catalytic active photocatalytic. ● Preparing membrane s with blended fibers to enhance its mechanical properties. ● In-situ growth of MoS 2 /TiO 2 via grafting treatment. ● Constructing three-phase reaction to enhance the yield of reactive radicals. ● Achieving performances of efficient, environmentally friendly and easy to recycle. [ABSTRACT FROM AUTHOR]

Abstract Pr 2-x Ca x NiMnO 6-δ (PCNMO x , x = 0.0–0.3) are prepared successfully by glycine-nitrate method. The effects of calcium doping to the crystal structure, the oxygen non-stoichiometry, and the cathode properties are evaluated by XRD, SEM, XPS and EIS. The double perovskite PCNMO x crystallize into a monoclinic structure with space group P2 1 /n. The unit cell volumes and thermal expansion coefficients increase systematically with Ca2+ doping, due to the gradual generation of oxygen vacancies in the lattice. Pr 2-x Ca x NiMnO 6-δ exhibits promising chemical compatibility with the electrolyte material Ce 0.9 Gd 0.1 O 1.95 (GDC) at 1200 °C. The electrochemical characterization results indicate that both oxygen vacancy concentration and electrical conductivity play important roles to cathode properties. The optimum composition Pr 1.8 Ca 0.2 NiMnO 6-δ shows the lowest polarization resistance of 0.18 Ω cm2 and highest peak power density of 0.3 W cm2 at 700 °C on GDC electrolyte supported fuel cell. The electrochemical impedance measurements under oxygen partial pressures, together with distribution of relaxation times analysis, identify three conjunctive elementary processes involved in the cathode reaction, and prove that the charge transfer process is the major rate-determining step of oxygen reduction reaction. Graphical abstract Image 1 Highlights • Calcium doping promotes the generation of oxygen vacancy in Pr 2-x Ca x NiMnO 6-δ. • Pr 1.8 Ca 0.2 NiMnO 6-δ exhibits comparable TEC with GDC electrolyte. • Pr 1.8 Ca 0.2 NiMnO 6-δ cathode shows the lowest Rp of 0.18 Ω cm2 at 700 °C. • DRT analysis identify three conjunctive elementary cathode processes. [ABSTRACT FROM AUTHOR]

For indoor facility agricultural plant growth lighting the far-red light is an important band, but there is a lack of efficient far-red LED phosphors. In this work, an efficient monoclinic double-perovskite far-red phosphor CaLaLiTeO 6 : Mn4+ was synthesized. The far-red light emission around 707 nm was realized by 468 nm blue light excitation. The internal quantum efficiency was measured to be 65.24 %. The structural analysis demonstrates that the small radius Ca2+ ions in the double-perovskite structure lead to the increase of [MnO 6 ]8- octahedron distortion and the enhancement of the covalent bonding of Mn-O bonds. The resulting low structural symmetry and strong covalent bonding increase the probability of the d-d transition of Mn4+, enhance the absorption intensity of the blue band in the excitation spectrum, and improve the far-red light emission efficiency. Far-red LED devices were fabricated by coating the synthesized CaLaLiTeO 6 : 0.6 %Mn4+ phosphors on 465 nm blue diodes. In the laboratory the growth experiments of wheats were carried out by using encapsulated LED devices, which proved that LED can effectively promote the growth of wheat. Our results shed a light on the exploration of efficient far-red phosphors for indoor plant growth lighting application. • A new double perovskite far-red phosphor CaLaLiTeO 6 : Mn4+ was synthesized. • Investigated the effect of Ca2+, Sr2+, Ba2+ on structure and luminescence properties. • Under the excitation of 468 nm blue light, far red light emission with IQE of 65.2 % is realized. • The encapsulated far red LEDs can promote the growth of wheat. [ABSTRACT FROM AUTHOR]

Electron beam smelting layered solidification technology is applied to prepare a nickel-based superalloy for turbine disks with service temperature up to 850 ℃. The microstructures, segregation and homogenization behavior were investigated. The results show that there is a cellular crystal structure with a width of 1.5 mm between the layers, and the dendritic structure is observed within the layers. The average secondary dendrite arming spacing is 28.6 µm, which attributed to higher temperature of molten pool and faster cooling rate. After electron beam smelting layered solidification technology, the macrosegregation is eliminated, and the microsegregation is weakened. The average temperature on the molten pool surface during electron beam smelting is 1813 K according to evaporation rates of Ni. The effect of homogenization treatment on the microstructures and microsegregation evolution was discussed. Based two diffusion models, the diffusion coefficient of Nb and W at 1190 °C are calculated as 7.365 × 10−16 m2/s and 5.805 × 10−16 m2/s, respectively. • The microstructure of GH4975 prepared by EBS-LST are significantly reduced compared with alloy prepared by VIM plus VAR. • Electron beam smelting layered solidification technology can eliminate macrosegregation and reduce microsegregation. • The average temperature of the melt during smelting is calculated as 1813 K according to the evaporation rate of Ni. • The diffusion coefficients of Nb and W in GH4975 alloy are calculated base on two diffusion models at 1190 °C. [ABSTRACT FROM AUTHOR]

• Zero-thermal quenching is achieved in ZnGa 2 O 4 : 0.02Eu3+ phosphor with spinel structure. • The DFT calculation reveals the existence of Zn vacancy defects can construct defect energy levels. • Defect energy levels can capture thermal ionization electrons and assist enhancing the fluorescence emission. • The prepared ZnGa 2 O 4 : 0.02Eu3+ red phosphors exhibit high color purity of 96%. By constructing appropriate defect energy levels, zero-thermal quenching was achieved in ZnGa 2 O 4 : 0.02Eu3+ phosphor under multi-wavelength excitation. [Display omitted] The struggle with "thermal load" is always an unavoidable challenge for photo-luminescent material. In this work, a novel red phosphor of ZnGa 2 O 4 : Eu3+ with spinel-type structure is prepared by high-temperature solid-phase method. Due to the charge imbalance during the replacement processes of Ga3+→Zn2+ and Eu3+→Zn2+ in mixed spinel structure, vacancy defects can be introduced into the lattice structure of ZnGa 2 O 4 : 0.02Eu3+. The results of Density Function Theory (DFT) calculation demonstrate that the existence of vacancy defects can construct defect energy levels in the energy band structure of the host crystal, which can assist enhancing the fluorescence emission intensity of the phosphor at high temperature. The strong thermal stability of its own structure combined with the assistance of defect energy levels enables the achievement of zero-thermal quenching in ZnGa 2 O 4 : 0.02Eu3+ under multi-wavelength excitation. Our results open up a new way for the exploration and utilization of zero-thermal quenching phosphors. [ABSTRACT FROM AUTHOR]